WASHINGTON -LRB- CNN -RRB- -- The man who revealed that Valerie Plame worked for the CIA said that he was `` extraordinarily foolish '' to leak her name .

Former Deputy Secretary of State Richard Armitage was a source of the CIA leak to columnist Robert Novak .

Former Deputy Secretary of State Richard Armitage told CNN 's Wolf Blitzer in an interview broadcast Sunday that he did not realize Plame was a covert agent when he discussed her with syndicated columnist Robert Novak .

Novak , a former CNN contributor , wrote the July 2003 column in which Plame was named as a CIA employee . He later cited his sources as Armitage and Karl Rove , then President Bush 's top political adviser .

Armitage said he had seen a memo that said Plame was publicly chairing a meeting , so he assumed her CIA employment was not a secret .

`` There was no ill intent on my part , and I had never seen , ever in 43 years of having a security clearance , a covert operative 's name in a memo , '' he said . Watch Armitage explain why he leaked Plame 's name ''

Blitzer asked Armitage if he `` simply assumed that she was not a clandestine officer of the CIA . ''

`` Well , even Mr. Novak has said that he used the word ` operative ' and misused it , '' Armitage said . `` No one ever said ` operative . ' And I not only assumed it , as I say , I have never seen a covert agent 's name in a memo . However , that does n't take away from what Mrs. Plame said . It was foolish , yes . ''

Rove , who left the White House in August , has denied he was also a source of the leak to Novak .

Plame 's identity was disclosed shortly after her husband , former U.S. Ambassador Joseph Wilson , challenged one of the chief claims underpinning the Bush administration 's case for the U.S. invasion of Iraq -- that Iraq had sought uranium for nuclear weapons from the African country of Niger .

In an op-ed piece for The New York Times , Wilson wrote that he had investigated the claim at the request of CIA officials and found it `` highly doubtful '' that any such transaction could have occurred , and he accused the Bush administration of having `` twisted '' the evidence for war .

Neither Armitage nor Rove was charged with a crime in the leak .

Wilson and Plame have accused Rove and other Bush officials of leaking her identity as a CIA officer in retaliation for her husband 's emergence as an administration critic .

A federal judge in Washington recently dismissed a lawsuit by the couple against Rove , Armitage , Vice President Dick Cheney and Cheney 's former chief of staff , Lewis `` Scooter '' Libby .

Libby was convicted of obstructing justice and perjury in the probe and sentenced to 30 months in prison , but Bush commuted his term before he had served any time . E-mail to a friend

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Richard Armitage says he had `` no ill intent '' when he revealed CIA agent 's name

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Armitage revealed Valerie Plame 's identity to columnist Robert Novak

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Former State Department official says he did n't know Plame was covert agent

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Plame 's husband -- Joseph Wilson -- was critical of Bush administration 's Iraq policy